diff --git a/src/effect/EffectSchemaTraitExpressionBuilder.ts b/src/effect/EffectSchemaTraitExpressionBuilder.ts
index a67c018..051e0cb 100644
--- a/src/effect/EffectSchemaTraitExpressionBuilder.ts
+++ b/src/effect/EffectSchemaTraitExpressionBuilder.ts
@@ -7,20 +7,32 @@ import { traitsUnique } from "../traitsUnique"
 
 
 export class EffectSchemaTraitExpressionBuilder<
-    Superclass   extends S.Class<unknown, Fields, A, I, R, C, Inherited, Proto>,
-    const Traits extends readonly Trait<any, any, any, any>[],
-
     Fields       extends S.Struct.Fields,
     A, I, R, C,
     Inherited    extends object,
     Proto,
+    Static       extends object,
+
+    const Traits extends readonly Trait<any, any, any, any>[],
 > {
     constructor(
-        readonly expressionSuperclass:  Superclass,
+        readonly expressionSuperclass:  S.Class<unknown, Fields, A, I, R, C, Inherited, Proto> & Static,
         readonly expressionTraits:      Traits,
     ) {}
 
 
+    class<NewFields extends S.Struct.Fields>(
+        identifier:    string,
+        fields:        NewFields,
+        annotations?:  S.Annotations.Schema<unknown>
+    ) {
+        return new EffectSchemaTraitExpressionBuilder(
+            S.Class<unknown>(identifier)(fields, annotations),
+            this.expressionTraits,
+        )
+    }
+
+
     extends<
         Super          extends S.Class<unknown, SuperFields, SuperA, SuperI, SuperR, SuperC, SuperInherited, SuperProto>,
 
@@ -58,13 +70,13 @@ export class EffectSchemaTraitExpressionBuilder<
     >(
         ...traits: T
     ): EffectSchemaTraitExpressionBuilder<
-        Superclass,
-        TraitExpressionBuilder.ExpressesReturnTypeTraits<Traits, T>,
-
         Fields,
         A, I, R, C,
         Inherited,
-        Proto
+        Proto,
+        Static,
+
+        TraitExpressionBuilder.ExpressesReturnTypeTraits<Traits, T>
     > {
         return new EffectSchemaTraitExpressionBuilder(
             this.expressionSuperclass,